Rats were exposed for extended times to low doses of chlordecone (1 and 6 ppm in the diet). After 105 days of exposure of female rats to this diet, levels of circulating prolactin and growth hormone were not significantly altered, but at the higher dose of chlordecone, hypothalamic beta-endorphin levels were selectively reduced. Since no changes were seen in pituitary levels of beta-endorphin of treated rats, chlordecone had some regional specificity. Levels of dopamine, serotonin, and their metabolites were unchanged in the caudate nucleus of female rats exposed to chlordecone. Thus, low levels of chlordecone appear to selectively affect hypothalamic beta-endorphin suggesting the hypothalamus may be especially sensitive to this neurotoxicant. The gestationally and lactationally-exposed female offspring of these rats showed a major increase in the levels of growth hormone at 100 days of age. However, other parameters assayed remained unaltered. These consisted of biogenic amines within the caudate nucleus, pituitary and hypothalamic met-enkephalin and circulating prolactin, growth hormone, and estrogen.